I think the downside to US is that if you do online check-in, you cannot choose your seat on the shuttle. If you can - please let me know how!!!!

(Aside - wife and I flying BOS-LGA shuttle today, booked in same PNR, OLCI puts us in 5A and 14F. I check seatmap (through manage reservations) and it shows only 8 seats assigned. US Airways internet help is useless since they cannot see the seatmap and dont understand why I am upset with the computer.)